- Added PARAM::alloced_sel_args where we count the # of SEL_ARGs
  created by SEL_ARG tree cloning operations.
- Made the range analyzer to shortcut and not do any more cloning 
  if we've already created MAX_SEL_ARGS SEL_ARG objects in cloning.
- Added comments about space complexity of SEL_ARG-graph 
  representation.


mysql-test/r/range.result:
  BUG#26624: Testcase
mysql-test/t/range.test:
  BUG#26624: Testcase